Tritium luminous paint

Deuterium is used as a moderator to slow down neutrons. Tritium atoms are also present but in much smaller proportions. Tritium is readily produced in nuclear reactors and is used in the production of the hydrogen (fusion) bomb. It is also used as a radioactive agent in making luminous paints, and as a tracer. 

Hydrogen forms three isotopes protium, deuterium, and tritium. Protium and deuterium can be separated by a variety of physical and chemical processes. Ordinary light hydrogen in H-X bonds can be replaced by deuterium, which then provides a means of following the progress of a variety of reactions. Heavy water is used as a moderator in fission reactors. Tritium, produced naturally in the upper atmosphere and artificially in fission reactors, is a mild beta emitter and is used as a tracer and to make luminous paints and self-luminous exit signs. 

Phosphors for radio-activation are used as mixtures with a ji-radioactive compound (e.g., 3H, 14C, or 147Pm compounds) whose radiation effects continuous luminescence of the phosphor. Tritium-labeled organic binders are used for the production of luminous products and paints. Because of the high cost of tritium, the phosphors must have a high efficiency. 

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